Welcome to the July 2019 DRB! The Dairy Research Bulletin delivers a brief synopsis of the most current Human, Animal, and Environmental dairy research that is going on in the World, and also that which is of special interest to California dairy producers and consumers alike.

If you would like to peruse the most pertinent dairy research from months past, then visit the Dairy Research Bulletin Archive


Selected Articles on Social Responsibility, Environmental Management, and Sustainability

Elevating dairy research and extension through partnership: Outcomes from the United States Department of Agriculture and National Dairy Council collaborative meeting to develop a coordination roadmap. Tricarico JM, Slimko ML, Graves WB, Eve MD, Thurston JA. J Dairy Sci. 2019 Jul 24. pii: S0022-0302(19)30650-2.

  • Dairy foods provide a significant portion of the recommended daily nutrition for much of the US population. Improving the availability of safe and nutritious dairy products and decreasing the environmental impact of the dairy community continue to be high priorities for both industry and the public sector.
  • In recognition of these shared priorities, scientists and other specialists from the USDA, National Dairy Council, industry, academia, and nongovernmental organizations participated in the “Elevating Dairy Research and Extension Through Partnership” meeting on June 19, 2018.
  • The purpose of the meeting was to strengthen partnerships and identify dairy-related research and extension needs in human nutrition, environmental sustainability, food safety, and product innovation that would benefit from enhanced coordination and collaboration across the dairy community, academia, and government.
  • To catalyze further progress on these topics, the meeting organizers agreed to leverage the content and expertise that emerged from the meeting to develop a dairy research and extension coordination roadmap. The roadmap will establish and articulate a vision for coordinated collaboration between USDA researchers, the National Dairy Council, university researchers, extension specialists, and other dairy community stakeholders in the private and public sectors.
  • This article represents the proceedings of the meeting and is intended to broadly communicate the dairy research and extension discussion and next steps to the dairy research and extension communities and other stakeholders in industry, academic, and government sectors.

A multi-platform inversion estimation of statewide and regional methane emissions in California during 2014-2016. Cui Y, Vijayan A, Falk M, et al.  Environ Sci Technol. 2019 Jul 26.

  • California adopted the landmark Global Warming Solutions Act of 2006 to reduce greenhouse gas emissions to the 1990 levels by 2020, and has also enacted several ambitious climate strategies to mitigate the global warming impacts of methane (CH4), such as Senate Bill No. 1383 which requires a 40% reduction in CH4 emissions below 2013 levels by 2030.
  • California methane (CH4) emissions are quantified for three years from two tower networks and one aircraft campaign.
  • In this study the researchers used backward trajectory simulations initialized by three inventories, to achieve the emission quantification.
  • The results show total statewide CH4 emissions of 2.05±0.26 teragrams/yr, which is 1.14 to 1.47 times greater than the anthropogenic emission estimates by California Air Resource Board (CARB). Some of differences could be biogenic emissions, super-emitter point sources, and other episodic emissions which may not be completely included in the CARB inventory.
  • San Joaquin Valley (SJV) has the largest CH4 emissions (0.94±0.18 teragrams/yr), followed by the South Coast Air Basin (0.39±0.18), the Sacramento Valley (0.21±0.04), and the San Francisco Bay Area (0.16±0.05). The dairy and oil/gas production sources in the SJV contribute 0.44±0.36 and 0.22±0.23 teragrams CH4/yr, respectively.
  • This study has important policy implications for regulatory programs, as it provides a thorough multi-year evaluation of the emissions inventory using independent atmospheric measurements and identifies opportunities for the expansion and applications of the monitoring network.

A heritable subset of the core rumen microbiome dictates dairy cow productivity and emissions. Wallace RJ, Sasson G, Garnsworthy PC, et al. Sci Adv. 2019 Jul 3;5(7):eaav8391.

  • The main members of the rumen microbiome are now well understood. Bacteria, which usually comprise most of the species richness, are widely persistent geographically across multiple ruminant species and individual animals, and many species can be considered symbiotic with ruminants, as they provide metabolic activities and products essential for the host
  • A 1000-cow study across four European countries was undertaken to understand to what extent ruminant microbiomes can be controlled by the host animal and to identify characteristics of the host rumen microbiome axis that determine productivity and methane emissions.
  • A core rumen microbiome, phylogenetically linked and with a preserved hierarchical structure, was identified. A 39-member subset of the core formed hubs in co-occurrence networks linking microbiome structure to host genetics and phenotype (methane emissions, rumen and blood metabolites, and milk production efficiency).
  • These phenotypes can be predicted from the core microbiome using machine learning algorithms. The heritable core microbes, therefore, present primary targets for rumen manipulation toward sustainable and environmentally friendly agriculture.

A qualitative study of Ontario dairy farmer attitudes and perceptions toward implementing recommended milking practices. Belage E, Croyle SL, Jones-Bitton A, Dufour S, Kelton DF. J Dairy Sci. 2019 Jul 17. pii: S0022-0302(19)30606-X.

  • Recommended milking practices are protective against mastitis. However, many producers do not adopt, or only partially adopt, these measures.
  • This study aimed to explore the attitudes and perceptions of Ontario dairy farmers toward barriers to implementation of recommended milking practices and to investigate what motivates behavior change in relation to milking hygiene.
  • Four focus groups with Ontario dairy producers were conducted and the results showed that the main barriers to adoption of recommended milking practices were identified and categorized into 2 groups: intrinsic barriers and physical barriers.
    • Intrinsic barriers included personal habits and convenience, not perceiving udder health as a priority on their farm, and lack of information.
    • Physical barriers included employee training and compliance, convenience of implementing RMP, and time, money, and labor barriers.
  • Lack of udder health problems translated for some producers into non-adoption of certain recommended milking practices, as they felt these practices were not needed unless a problem arose. Others felt motivated to implement more practices and work toward better udder health if such efforts translated into rewards for better-quality milk.
  • Some producers perceived recommended milking practices as not meaningful or useful, seemingly due to a lack of education about the reasons behind recommended milking practices implementation.
  • Understanding the importance of these practices is one key to implementing them. To overcome some of the intrinsic barriers, increased efforts in knowledge translation are needed, including efforts in retraining current practices, as well as in establishing best practices.

Dairy farm management practices and the risk of contamination of tank milk from Clostridium spp. and Paenibacillus spp. spores in silage, total mixed ration, dairy cow feces, and raw milk. Borreani G, Ferrero F, Nucera D, Casale M, Piano S, Tabacco E. J Dairy Sci. 2019 Jul 17. pii: S0022-0302(19)30620-4.

  • The occurrence of Paenibacillus and Clostridium spores in silage is of great concern for dairy producers because their spores can contaminate milk and damage processed milk and semi-hard cheeses. Spoiled silage is considered to be the main contamination source of the total mixed ration, feces of dairy cows, and consequently bulk tank milk via the contamination of cow teats by dirt during milking.
  • The presence of an anaerobic and facultative anaerobic sporeformer population in different matrices (soil, corn silage, other feeds, total mixed ration, feces, and milk) and its transmission pathway has been studied on 49 dairy farms by coupling plate count data with 16S-DNA identification.
  • The different matrices have shown a high variability in the anaerobic and facultative anaerobic spore count, with the highest values being found in the aerobically deteriorated areas of corn silages. Clostridium tyrobutyricum, Paenibacillus macerans, and Paenibacillus thermophylus were detected in all the matrices.
  • The total mixed ration spore count was influenced by the amount of spoiled corn silage in the total mixed ration and by the care taken when cleaning the spoiled silage before feed-out. Most of the farms that prevent the presence of visible moldy silage in the silo and carefully clean to remove molded spots were able to maintain their total mixed ration spore counts below 4.0 log spores/g.
  • Moreover, the higher the number of spores in feces, the higher the number of spores in the milk. Most of the farms that presented a feces contamination greater than 5.0 log spores/g had a higher milk spore contamination than 1,000 spores/L.
  • Careful animal cleaning and good milking practices have been found to be essential to maintain low levels of contamination in bulk tank milk, but it has emerged that only by coupling these practices with a correct silage management and cleaning during total mixed ration preparation can the contamination of milk by spores be kept at a low level.
  • It has been found that aerobically deteriorated silage has a great capacity to contaminate total mixed ration and consequently to increase the risk of milk spore contamination, even when routine milking practices are adopted correctly.

Understanding Cows’ Emotions on Farm: Are Eye White and Ear Posture Reliable Indicators? Battini M, Agostini A, Mattiello S. Animals (Basel). 2019 Jul 24;9(8). pii: E477.

  • Understanding the emotions of dairy cows is primarily important in enhancing the level of welfare and provide a better life on farm.
  • This study explored whether eye white and ear posture can reliably contribute to interpret valence and arousal of emotions in dairy cows.
  • The research was conducted in five Italian dairy farms. Four hundred and thirty-six photographs of cows’ heads were scored (four-level), according to the eye white and ear posture during feeding, resting, pasture, and an avoidance distance test at the feeding rack (ADF test).
  • Eye white and ear posture were significantly correlated and influenced by the context. Pasture was the most relaxing context for cows (67.8% of half-closed eyes; 77.3% ears hung down or backwards). The excitement during ADF test was high, with 44.8% of eye white being clearly visible and ears directed forwards to the approaching assessor (95.5%).
  • Housing and management mostly influenced emotions during feeding and resting (P = 0.002 and P = 0.001, respectively): where competition for feeding places and cubicles was low, the cows showed the highest percentages of half-closed eyes and ears backwards or hung down.
  • This research supports the use of eye white and ear posture as reliable indicators of emotions in dairy cows.

Determining the economic value of daily dry matter intake and associated methane emissions in dairy cattle. Richardson CM, Baes CF, Amer PR, Quinton C, Martin P, Osborne VR, Pryce JE, Miglior F. Animal. 2019 Jul 22:1-9.

  • Feed represents a substantial proportion of production costs in the dairy industry and is a useful target for improving overall system efficiency and sustainability.
  • The objective of this study was to develop methodology to estimate the economic value for a feed efficiency trait and the associated methane production relevant to Canada.
  • The study approach quantifies the level of economic savings achieved by selecting animals that convert consumed feed into product while minimizing the feed energy used for inefficient metabolism, maintenance and digestion.
  • Overall, increasing the feed performance estimated breeding value by one unit (i.e. 1 kg of more efficiently converted dry matter intake during the cow’s first lactation) translates to a total lifetime saving of 3.23 kg in dry matter intake and 0.055 kg in methane with the economic values in Canadian dollars of $0.82 and $0.07, respectively.
  • Therefore, the estimated total economic value for feed production is $0.89/unit. The proposed model is robust and could also be applied to determine the economic value for feed efficiency traits within a selection index in other production systems and countries.


Selected Articles on Dairy Intake and Human Health

Associations of types of dairy consumption with adiposity: cross-sectional findings from over 12,000 adults in the Fenland Study, UK. Trichia E, Imamura F, Brage S, De Lucia Rolfe E, Griffin SJ, Wareham NJ, Forouhi NG. Br J Nutr. 2019 Jul 25:1-18.

  • Evidence from randomized controlled trials supports beneficial effects of total dairy products on body weight, fat and lean mass, but evidence on associations of dairy types with distributions of body fat and lean mass is limited.
  • This study aimed to investigate associations of total and different types of dairy products with markers of adiposity, and body fat and lean mass distribution.
  • The researchers evaluated cross-sectional data from 12,065 adults aged 30 to 65 years recruited to the Fenland study between 2005 and 2015 in Cambridgeshire UK.
  • The results showed that low-fat dairy consumption was inversely associated with visceral-to-subcutaneous fat ratio estimated with dual energy X-ray absorptiometry. Habitual consumption per serving/day (200 g) of milk was associated with 0.33 kg higher lean mass.
  • These findings suggest that the influence of milk consumption on lean mass and of low-fat dairy consumption on fat mass distribution may be potential pathways for the link between dairy consumption and reduced metabolic risk.

Full-Fat Dairy Food Intake is Associated with a Lower Risk of Incident Diabetes Among American Indians with Low Total Dairy Food Intake. Kummer K, Jensen PN, Kratz M, Lemaitre RN, Howard BV, Cole SA, Fretts AM. J Nutr. 2019 Jul 1;149(7):1238-1244.

  • Diet plays a key role in development of diabetes, and there has been recent interest in better understanding the association of dairy food intake with diabetes.
  • This study examined the associations of full-fat and low-fat dairy food intake with incident diabetes among American Indians-a population with a high burden of diabetes.
  • The study included participants from the Strong Heart Family Study, a family-based study of cardiovascular disease in American Indians, free of diabetes at baseline (2001-2003) (n = 1623).
  • After 11 years of follow-up, the overall intake of dairy was low, but participants who reported the highest full-fat dairy food intake had a lower risk of diabetes compared to those who reported the lowest full-fat food dairy intake. Low-fat dairy food intake was not associated with diabetes.
  • These findings may be of interest to populations with low dairy food intake as higher fat dairy may have more protective effects against the development of diabetes in these populations.

Dairy Product Consumption and Bladder Cancer Risk: A Meta-Analysis. Wu J, Yu Y, Huang L, Li Z, Guo P, Xu YW. Nutr Cancer. 2019 Jul 11:1-9.

  • Dairy products are an important part of the human diet; they are a source of fat, calcium, vitamin A, and many other essential elements of human health. In ecological and experimental research, dairy products are considered a possible protective factor against certain cancers.
  • The objective of this meta-analysis was to explore the potential relationship between dairy product consumption and bladder cancer risk.
  • The researchers extracted data from 16 studies on milk and 10 studies on dairy products. The total study population included 220,952 individuals.
  • Dairy product intake and bladder cancer risk were significantly associated, and milk intake and bladder cancer risk more so. The researchers found that dairy consumption was associated with a 14% reduction in bladder cancer risk while milk consumption was associated with 26% reduction.
  • This study shows an inverse association between milk and dairy consumption and bladder cancer risk.

Effects of Conventional Milk Versus Milk Containing Only A2 β-Casein on Digestion in Chinese Children: A Randomized Study. Xiaoyang S, Zailing L, Ni J, Yelland G. J Pediatr Gastroenterol Nutr. 2019 Jul 9. (This study was funded by the A2 Milk Company)

  • Milk or dairy intolerance is more prevalent in Chinese adults and children than in their Western or European counterparts. This undesirable physiological response is primarily attributed to genetic polymorphisms of the lactase gene leading to lower activity of gastrointestinal lactase. However, there is increasing evidence that the effects of dairy products on gastrointestinal dysfunction may be at least partially attributed to the proteolytic release of the bioactive peptide beta-casomorphin-7 (BCM-7) from β-casein, rather than lactose intolerance.
  • In this study, the researchers hypothesized that replacing conventional milk, which contains A1 and A2 β-casein (A1 milk), with milk that contains only A2 β-casein (A2 milk) in the diet of dairy or milk-intolerant preschoolers would result in reduced gastrointestinal symptoms associated with milk intolerance, and that this would correspond with cognitive improvements.
  • This randomized, double-blind, crossover study aimed to compare the effects of 5 days’ consumption of conventional milk versus A2 milk on gastrointestinal symptoms. The study also aimed to compare changes in the cognitive behavior of preschoolers.
  • The results showed that subjects who consumed A2 milk had significantly less severe gastrointestinal symptoms, reduced stool frequency, and improvements in stool consistency, compared with subjects consuming conventional milk. There were significant increases from baseline in serum interleukin-4, immunoglobulins G, E, and G1, and beta-casomorphin-7 coupled to lower glutathione levels, in subjects consuming conventional rather than A2 milk.
  • Cognitive impairment test analysis showed significant improvements in test accuracy after consumption of A2 milk. There were no severe adverse events related to consumption of either milk product.
  • Replacing conventional milk with A2 milk reduced gastrointestinal symptoms associated with milk intolerance in Chinese preschool children, with corresponding improvements in aspects of cognitive performance.

Daily Intake of Fermented Milk Containing Lactobacillus casei Shirota (Lcs) Modulates Systemic and Upper Airways Immune/Inflammatory Responses in Marathon Runners. Vaisberg M, Paixão V, Almeida EB, Santos JMB, Foster R, Rossi M, Pithon-Curi TC, Gorjão R, Momesso CM, Andrade MS, Araujo JR, Garcia MC, Cohen M, Perez EC, Santos-Dias A, Vieira RP, Bachi ALL. Nutrients. 2019 Jul 22;11(7). pii: E1678.

  • Although Lactobacillus casei Shirota (LcS) can benefit the immune status, the effects of LcS in the immune/inflammatory responses of marathon runners has never been evaluated.
  • Researchers evaluated the effect of daily ingestion of fermented milk containing or not LcS in the systemic and upper airway immune/inflammatory responses before and after a marathon.
  • Forty-two male marathon runners ingested a fermented milk containing 40 billion of LcS/day (LcS group, n= 20) or placebo (unfermented milk, n = 22) during 30 days pre-marathon.
  • The results showed higher proinflammatory cytokine levels in serum and nasal mucosa, and also lower salivary levels of SIgA and antimicrobial peptides, were found immediately post-marathon in the placebo group compared to other time points and to LcS group. Oppositely, higher anti-inflammatory levels and reduced neutrophil infiltration on nasal mucosa were found in the LcS group compared to other time points and to the placebo group.
  • For the first time, this study provides evidence that LcS is able to modulate the systemic and airways immune responses post-marathon.

A Vitamin D, Calcium and Leucine-Enriched Whey Protein Nutritional Supplement Improves Measures of Bone Health in Sarcopenic Non-Malnourished Older Adults: The PROVIDE Study. Hill TR, Verlaan S, Biesheuvel E, Eastell R, Bauer JM, Bautmans I, Brandt K, Donini LM, Maggio M, Mets T, Seal CJ, Wijers SL, Sieber C, Cederholm T, Aspray TJ; PROVIDE Consortium. Calcif Tissue Int. 2019 Jul 23.

  • Alterations in musculoskeletal health with advanced age contribute to sarcopenia and decline in bone mineral density and bone strength. This decline may be modifiable via dietary supplementation.
  • To test the hypothesis that a specific oral nutritional supplement can result in improvements in measures of bone health. Participants (n 380) were participants of the PROVIDE study, a 13-week, multicenter, randomized, controlled, double-blind, 2 parallel-group study among non-malnourished older participants (≥ 65 years old) with sarcopenia.
  • Supplementation of a vitamin D, calcium and leucine-enriched whey protein drink that comprises a full range of micronutrients (active; 2/day) was compared with an iso-caloric control.
  • The results showed that serum vitamin D concentrations increased from 51.1 ± 9nmol/L (mean ± SD) to 78.9 ± 21.1 nmol/L in the active group. Serum parathyroid hormone showed a significant treatment difference with a decline in the active group and increase in the control group. Serum IGF-1 increased in the active group. Serum CTX showed a greater decline in the active group.
  • Total body bone mineral density showed a small but significant increase in the active group after supplementation. Consuming a vitamin D, calcium and leucine-enriched whey protein supplement for 13 weeks improved serum vitamin D, suppressed parathyroid hormone, and had small but positive effects on bone mineral density, indicative of improved bone health, in sarcopenic non-malnourished older adults.

A Global Review of Food-Based Dietary Guidelines. Herforth A, Arimond M, Álvarez-Sánchez C, Coates J, Christianson K, Muehlhoff E. Adv Nutr. 2019 Jul 1;10(4):590-605.

  • The objective of this review is to provide a concise, descriptive global review of current food-based dietary guidelines, and to assess similarities and differences in key elements of a healthy diet articulated across countries.
  • Food-based dietary guidelines are currently available for 90 countries globally: 7 in Africa, 17 in Asia and the Pacific, 33 in Europe, 27 in Latin America and the Caribbean, 4 in the Near East, and 2 in North America.
  • This review provides summaries of the key messages and food guides that are used to communicate national dietary guidance, organized by food group, and evaluates the extent to which each set of food-based dietary guidelines includes existing recommendations articulated by the WHO.
  • Some guidance appears nearly universally across countries: to consume a variety of foods; to consume some foods in higher proportion than others; to consume fruits and vegetables, legumes, and animal-source foods; and to limit sugar, fat, and salt. Guidelines on dairy, red meat, fats and oils, and nuts are more variable.
  • Although WHO global guidance encourages consumption of nuts, whole grains, and healthy fats, these messages are not universally echoed across countries. Future frontiers in food-based dietary guidelines development include the incorporation of environmental sustainability and increased attention to sociocultural factors including rapidly changing dietary trends.
  • Steps toward regional and global dietary recommendations could be helpful for refinement of country-level food-based dietary guidelines, and for clear communication and measurement of diet quality both nationally and globally.